In DSSC (Dye-Sensitized Solar Cell), dye molecules are chemically absorbed by metal oxide semiconductor nanoparticles; then, the nanoparticles are spread on the cathode to function as a photosensitive layer; an electrolyte is interposed between the photosensitive layer and the anode to assist in electric conduction. DSSC has the following advantages:    1. The photosensitive particles have an effective light absorption area 100 times greater than the surface area of the electrode. Therefore, DSSC has very high light absorption efficiency, using a very small amount of material.    2. The photosensitive particles are fabricated via merely soaking the semiconductor particles in a dye solution and drying the particles with an inert gas. Therefore, DSSC has a simple and inexpensive fabrication process.    3. The dye of DSSC has a wide absorption spectrum in the range of visible light. Therefore, a single type of DSSC elements can harness a wide spectrum of solar light.    4. DSSC is semitransparent and suitable to be a construction material, especially a window material. For example, DSSC may be used as glass curtain walls of high-rise buildings to provide functions of sunlight sheltering, thermal insulation and power generation. Therefore, a building may have efficacies of power saving and power generation via using DSSC.
Generally, a solar cell is expected to have low cost, low fabrication complexity, and high photovoltaic conversion efficiency. DSSC indeed has the characteristics of low cost and low fabrication complexity. However, the photovoltaic conversion efficiency thereof still needs improving. A R.O.C patent publication No. 201001724 disclosed a “Dye Sensitized Solar Cell Having a Double-Layer Nanotube Structure and Manufacture Method Thereof”. The nanotube structures can increase the electric conduction efficiency of DSSC. However, nanotubes have less area to absorb dye than nanoparticles. Thus is decreased the photovoltaic conversion efficiency of the prior-art DSSC.